To the vociferous power duo Japandroids, rock, it seems, can be an adjective, noun, or verb. In a sprawling set at a nearly packed DC9 last night, the Vancouver band—shambolic, self-conscious, in its best moments inspired—played the bulk of its well-received 2009 debut, Post-Nothing, while rarely failing to remind an appreciative audience just how hard it intended to rock.

To wit: Japandroids’ set was heavy on foreplay and harder on banter, and throughout, guitarist Brian King promised that he and drummer David Prowse would “rock hard,” “commence rock,” and “rock out.” He asked the audience to forgive an obscure tune with “extensive rocking on our behalf,” and seemed to apologize for two concise, angular numbers that, one supposes, didn’t rock hard enough. The audience didn’t mind, of course; they were too busy … well, you know.

King and Prowse play noisy, unburdened indie rock (though neither “noise” nor “indie” feels especially apt) that doesn’t seek to inspire deep thoughts. Their lyrics don’t get much more thematically complex than “I don’t wanna worry ’bout dyin’/I just wanna worry ’bout sunshine girls,” from their best song, “Young Hearts Spark Fire,” which became a raucous singalong last night.

Yet to judge by their live show—with its precise musicianship and emotive gang vocals, but a slightly anxious stage presence—it’s clear these guys think a lot about their craft. The immediate reference points are propulsive, vaguely conceptual rockers like Les Savy Fav and Mclusky (Japandroids closed the set with the latter’s “To Hell With Good Intentions”), but to see such groups was like witnessing ids with instruments. King and Prowse aren’t quite comfortable enough in their skins to match such abandon, even if their most anthemic songs are up to muster. Strangely, that awkward dichotomy mostly proved a boon last night.

That’s because Japandroids meant every lyric, gesture, and raw chord. In “The Boys Are Leaving Town,” King and Prowse swooped yearningly downward on the final word of “will we find our way back home?” while keeping their mouths angled at the tips of their mics. Often, the wiry King ascended Prowse’s bass drum, a rock move remarkable only for the fact that the guitarist underwent surgery for a perforated ulcer this spring. With a Mclusky or Les Savy Fav (or, to go a degree further, a Queens of the Stone Age or Andrew W.K.), there’s always a degree of facetiousness. Japandroids, meanwhile, are the type of guys who take This Is Spinal Tap as seriously as Don’t Look Back. To them, rocking out is no joke.

DC’s Tennis System, who opened, shared Japandroids’ big-sound, small-scope ethos, if not the aesthetic. The four-piece played arena music scaled (sometimes awkwardly) to club size, a shoegaze-indebted space rock with soft edges, in which bursts of feedback occasionally melted into hooks.

Toronto’s (aptly if redundantly named) Slim Twig had less in common. Following Tennis System, this art-damaged, pompadoured troubadour played a short set of tortured, carnivalesque post-punk, a more acid-tinged take on the sort of Farfisa-heavy art punk pioneered by Suicide. Drenched in reverb, Slim Twig (né Max Turnbull) also had the between-song stuff down: “My banter is on par tonight!” he announced toward the end of his set. “Fuck! I’m doing so good!“